--- dwm.c
+++ dwm.c
@@ -177,6 +177,7 @@ static void grabkeys(void);
 static void incnmaster(const Arg *arg);
 static void keypress(XEvent *e);
 static void killclient(const Arg *arg);
+static void layoutmenu(const Arg *arg);
 static void manage(Window w, XWindowAttributes *wa);
 static void mappingnotify(XEvent *e);
 static void maprequest(XEvent *e);